What is Electrical Conductivity?
Electrical conductivity is a measure of a material’s ability to allow the transfer of electrons from one atom to another. This property is affected by the number of free electrons in a material, and thus the conductivity increases with increase in the number of free electrons. This property is of particular importance for many materials, especially in the electronics and engineering industries.
Electrical conductivity arises due to the presence of free electrons which act as charge carriers and can move from one atom to another. In materials such as metals, the free electrons are responsible for most of the movement of electric charge. This movement is either drift or diffusion; drift is the actual movement of the electrons through the metal while diffusion is a random movement due to collisions with other electrons.
The conductivity of the materials is often quantified by the magnitude of current passing through it and is denoted by the unit of siemens per meter (S/m). Conductivity is characterized by the presence of an electric field that causes the electrons to move freely within the material, resulting in the transfer of electric current. Conductivity is also related to resistance, as the two are inversely proportional.
The conductivity of a material may vary significantly depending on the type of material. In general, the conductivity of metals is much higher than of non-metals. The conductivity of metals can vary from that of a few metallic alloys up to 80,000 Siemens per meter. On the other hand, non-metals such as glass and ceramic are insulators, with a conductivity close to zero.
There are several factors that affect the electrical conductivity of a material. These include temperature, pressure, composition, and the presence of ions and impurities. As the temperature increases, so does the conductivity of a material due to the increased mobility of the electrons. Pressure also affects the conductivity due to its influence on the electron density of the material, though this effect is more prominent in some materials than others. Chemical composition also affects the conductivity due to the different types of electrons in the material. Certain elements, such as tin and cadmium, are more conductive than others, such as boron.
Impurities, such as certain ions or defects in the lattice structure, can adversely affect the conductivity of a material. The presence of impurities can also reduce the movement of electrons and prevent them from moving freely, thus reducing the overall conductivity.
Evaluating electrical conductivity is important for a wide range of applications in electronics and engineering. It is important for industries to develop materials that have high electrical conductivity and low noise levels. The development of materials with improved conductivity is an ever-evolving field and is the basis of many technological advancements.
